Small, light and stacks of enthousiasm...already caught a couple of rabbits. You're on the right track it sounds.
All longears are difficult, esspecially when there is a lot of cover. Open space, young hares would be best if you have access to that, slip as closely as possible. Otherwise I don't know. Get a a whippet too, to push them out and make them turn so the bigger dog can strike?
...small and light...do you have any pics?
Here's a link to afghans in the COO...but you prolly have already seen that....
http://www.afghanhoundsinternational.net/gallery/tazi
L